Amsterdam soil too expensive for private housing

According to projectdevelopers, the soil in Amsterdam is to expensive to build private housing. The city needs these properties, but project developers are not making enough money on these properties. They earn more on social housing and condominiums, since these properties are funded by the Government. Project developers say that this problem can be easily solved by setting more requirements for building houses. This way there will be a better mix of condominiums, private housing and social housing.